The study has been designed to find the best dose of this drug. This means groups of patients will get different doses of procarbazine until patients have major side effects. Once I am assigned to a dose, it will not be increased. I will be given the same or a lower dose if indicated, throughout my treatment. The study will also be looking at the side effects of procarbazine and the levels of this drug in my blood. This study will be conducted at up to nine sites. The total number of patients being studied will be 6 persons per dose level until the best does is found.